optparse.coffee | |
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A simple OptionParser class to parse option flags from the command-line. Use it like so:
The first non-option is considered to be the start of the file (and file option) list, and all subsequent arguments are left unparsed. | exports.OptionParser = class OptionParser |
Initialize with a list of valid options, in the form:
Along with an an optional banner for the usage help. | constructor: (rules, banner) ->
@banner = banner
@rules = buildRules rules |
Parse the list of arguments, populating an | parse: (args) ->
options = arguments: []
args = normalizeArguments args
for arg, i in args
isOption = !!(arg.match(LONG_FLAG) or arg.match(SHORT_FLAG))
matchedRule = no
for rule in @rules
if rule.shortFlag is arg or rule.longFlag is arg
value = if rule.hasArgument then args[i += 1] else true
options[rule.name] = if rule.isList then (options[rule.name] or []).concat value else value
matchedRule = yes
break
throw new Error "unrecognized option: #{arg}" if isOption and not matchedRule
if not isOption
options.arguments = args[i...args.length]
break
options |
Return the help text for this OptionParser, listing and describing all
of the valid options, for | help: ->
lines = ['Available options:']
lines.unshift "#{@banner}\n" if @banner
for rule in @rules
spaces = 15 - rule.longFlag.length
spaces = if spaces > 0 then Array(spaces + 1).join(' ') else ''
letPart = if rule.shortFlag then rule.shortFlag + ', ' else ' '
lines.push ' ' + letPart + rule.longFlag + spaces + rule.description
"\n#{ lines.join('\n') }\n" |
Helpers | |
Regex matchers for option flags. | LONG_FLAG = /^(--\w[\w\-]+)/
SHORT_FLAG = /^(-\w)/
MULTI_FLAG = /^-(\w{2,})/
OPTIONAL = /\[(\w+(\*?))\]/ |
Build and return the list of option rules. If the optional short-flag is
unspecified, leave it out by padding with | buildRules = (rules) ->
for tuple in rules
tuple.unshift null if tuple.length < 3
buildRule tuple... |
Build a rule from a | buildRule = (shortFlag, longFlag, description, options) ->
match = longFlag.match(OPTIONAL)
longFlag = longFlag.match(LONG_FLAG)[1]
options or= {}
{
name: longFlag.substr 2
shortFlag: shortFlag
longFlag: longFlag
description: description
hasArgument: !!(match and match[1])
isList: !!(match and match[2])
} |
Normalize arguments by expanding merged flags into multiple flags. This allows
you to have | normalizeArguments = (args) ->
args = args.slice 0
result = []
for arg in args
if match = arg.match MULTI_FLAG
result.push '-' + l for l in match[1].split ''
else
result.push arg
result
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